The star of Andrew Rawnsley's new book about New Labour is Alistair Darling's wife, Maggie: a flash of colourful ­humanity in the gloomy sky of ministers who are just swearing at each other because they can. Rawnsley mentions her, in passing, as he discusses a period when Darling apparently faced the sack, and regular leaks were making it out of Downing Street. "[Maggie Darling] could not contain her fury that the chancellor was being so brazenly traduced from next door. She blew up to one friend: 'The fucking cunts are trying to stitch up Alistair! The cunts! I can't ­believe they're such cunts!'"

Well, this is proper swearing – you can't imagine Sarah Brown swearing like that, human-face of Gordon or not. I think I am going to make Top Trumps cards, in time for the election, pitting all the spouses' powers against one another (Ah ha! Yours is posh, but mine swears like a sailor).

Maggie Darling, nee Vaughan, had blipped once across the pol­itical radar when Michelle Obama called her "a true firebrand"; but who knew what that was based on? In the curious carousel of ­activities arranged for Mrs Obama during her visit last spring (mainly, "Here are some successful women from the UK – a model there, an author here, all of them ­successful. And not one of them a man"), maybe all you had to do was look feisty. Otherwise, her profile has been low, give or take the odd quip to a journalist. "My husband now owns four banks," she said recently, "and that incurs a lot of paperwork."

You would think there'd be more dirt, sorry, information, on someone who worked as a journalist until the 1997 election victory, first on Radio Forth, later the Daily Record and the Glasgow Herald. One colleague remembers someone hugely respected, fun, political, keen on social justice long before it was fashionable. Colleagues at the Herald remember nothing especially potty-mouthed about her, counter­ing with pride that "everybody was like that at the Glasgow Herald".

Guardian writer Decca Aitkenhead, who met the Darlings at home in Scotland, says, "She is genuinely irresistible. I can't quite imagine anybody who wouldn't like her." Unless you traduce her fella. Then there's trouble.